A novel lightweight metamaterial with ultra broadband electromagnetic wave absorption induced by three-dimensional CNTs conductive-coated arrays

Lightweight metamaterials for broadband electromagnetic wave absorption have become a significant requirement for electromagnetic interference and stealth technologies. In this study, a novel lightweight metamaterial absorber with three-dimensional (3D) carbon nanotubes (CNTs) conductive-coated arrays is designed and fabricated through 3D printing and dipping process, which realized less than −10 dB reflection loss in the frequency range of 7.0–40 GHz. The effect of the sheet resistance of CNTs conductive coatings and geometric parameters of meta-structure on the frequency-dependent absorption properties is investigated, and the improved absorbing efficiency is discussed based on the synergy effect of multiscale structures of 3D conductive-coated arrays. Moreover, the volume of the proposed ultra broadband absorber is reduced by approximately 60.5% compared with that of the dense plate structure, indicating a significant lightening with efficient absorbing capacities. Additionally, the absorption bandwidth and intensity of the proposed absorber have insensitive changes with the variation of incident angle. Therefore, an ultra broadband electromagnetic absorption is designed and realized, indicating a promising lightweight ultra broadband electromagnetic absorbing candidate for lightweight metamaterial absorbers.